The combination of tramadol and morphine may be recommended for postoperative analgesia

Improving pain control during transarterial chemoembolization for hepatocellular carcinoma performed under local anesthesia with multimodal analgesia

PURPOSE

The purpose of this study was to assess the performance of a reinforced analgesic protocol (RAP) on pain control in patients undergoing conventional trans-arterial chemoembolization (cTACE) for hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Eighty-one consecutive patients (57 men, 24 women) with a mean age of 69 ± 10 (standard deviation) years (age range: 49-92 years) underwent 103 cTACEs. Standard antalgic protocol (50 mg hydroxyzine, 10 mg oxycodone, 8 mg ondansetron, and lidocaine for local anesthesia) was prospectively compared to a RAP (standard + 40 mg 2-h infusion nefopam and 50 mg tramadol). The individual pain risk was stratified based on age, the presence of cirrhosis and alcoholic liver disease, and patients were assigned to a low-risk group (standard protocol) or high-risk group (RAP). The primary endpoint was severe periprocedural abdominal pain (SAP), defined as a visual analog scale score ≥30/100. A predefined intermediate analysis was performed to monitor the benefit-risk of the RAP. Based on the intermediate analysis, all patients were treated with the RAP.

RESULTS

The intermediate analysis performed after 52 cTACE showed that 2/17 (12%) high-risk patients (i.e., those receiving the RAP) experienced SAP compared to 15/35 (43%) low-risk patients (odds ratio [OR] = 0.18; 95% confidence interval [CI]: 0.02-0.98; P = 0.03). Analysis of all procedures showed that 12/67 (18%) patients in cTACE receiving the RAP experienced SAP compared to 15/36 (42%) patients who did not receive it (OR = 3.27; 95% CI: 1.32-8.14; P = 0.01). There were no statistical differences in adverse events, particularly for nausea, between groups.

CONCLUSION

Reinforcing the analgesic protocol by combining non-opioid and opioid molecules reduces perioperative pain in patients undergoing cTACE for HCC.

The analgesic interaction of tramadol and morphine in rats: An isobolographic study

In order to assess possible synergistic antinociceptive interactions, the analgesic effects of intra-peritoneal tramadol and morphine administered either separately or in combination were determined using tail-flick latency test following exposure to radiant heat in rats. Groups of eight male Sprague-Dawley rats received either tramadol (3.90, 7.00, 12.50, and 22.20 mg kg^-1) and morphine (1.26, 2.25, 4.00 and 7.10 mg kg^-1) or a combination of tramadol and morphine (4 different combinations). The baseline latency was obtained before drug injection for each rat, then at 15, 30, 45, 60 and 75 min after injection. The effective dose (ED)₅₀ for either tramadol or morphine individually was 11.70 mgkg^-1 and 2.26 mg kg^-1, respectively. Based on isobolographic analysis, the ED₅₀ values obtained by drug combination were significantly less than the calculated additive values; which indicates that the co-administration of tramadol and morphine produces synergistic antinociception in the radiant heat tail-flick assay. Combination of morphine and tramadol administered intra-peritoneally can be used for the control of acute pain in rats.